We first compare the perplexity of CWVAE with baseline methods. Perplexity measures the probability of model to regenerate the exact targets, which is particular suitable for evaluating the model performance on one-to-many problem [1]}. Further, we employ BLEU score to evaluate the accuracy of generations [2]}, and the number of distinct n-gram to evaluate the diversity of generations [3]}. The distinct is normalized to \([0, 1]\)  by dividing the total number of generated tokens.
